# def write_three_lines(filename,massage):
#     with open("hello.txt","w") as f:
#         f.write(massage)

# if __name__ == "__main__":
#     write_three_lines("hello.txt","Line1\n Line2\n Line3\n")
#     with open("hello.txt","r") as f:
#         content = f.read()
#         print("内容是\n",content)

def write_three_lines(filename):
    with open("hello.txt","w") as f:
        f.write("Line1\n Line2\n Line3\n")

if __name__ == "__main__":
    write_three_lines("hello.txt")
    with open("hello.txt","r") as f:
        content = f.read()
        print("内容是\n",content)